Randy Wright and Ricardo Lagos are among the big guys in the field. They also go by the moniker "new monetarists". The models generally start from the foundation that product markets are subject to search and matching frictions with limited commitment to repay debts, and fiat money can have value by resolving the commitment issue. I always saw them as overly complicated ways to derive money demand functions.
Randy Wright and Steve Williamson have a chapter surveying the literature in the Handbook of Monetary Economics v3.
